The invention relates to a series connection hydraulic circuit, and belongs to the technical field of hydraulic equipment. The series connection hydraulic circuit comprises a first hydraulic motor and a second hydraulic motor, and further comprises a pressure compensation valve. A port A, a port B and a port T are arranged on the pressure compensation valve. The port A is connected with an inlet of the first motor, the port B is connected with an inlet of the second motor, and the port T is connected with an oil tank. According to the series connection hydraulic circuit, a pressure compensation valve is added, the torque distribution function is achieved, the cavitation phenomenon of the second hydraulic motor is avoided, and meanwhile the output rotating speed of the hydraulic motors will not be lowered.